1 files changed, 53 insertions, 24 deletions

diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 142ab6aa2aa1..ce103e7b0bc3 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -189,14 +189,30 @@ static int autofs4_getpath(struct autofs_sb_info *sbi,
         return len;
 }
 
+static struct autofs_wait_queue *
+autofs4_find_wait(struct autofs_sb_info *sbi,
+                  char *name, unsigned int hash, unsigned int len)
+{
+        struct autofs_wait_queue *wq;
+
+        for (wq = sbi->queues; wq; wq = wq->next) {
+                if (wq->hash == hash &&
+                    wq->len == len &&
+                    wq->name && !memcmp(wq->name, name, len))
+                        break;
+        }
+        return wq;
+}
+
 int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                 enum autofs_notify notify)
 {
+        struct autofs_info *ino;
         struct autofs_wait_queue *wq;
         char *name;
         unsigned int len = 0;
         unsigned int hash = 0;
-        int status;
+        int status, type;
 
         /* In catatonic mode, we don't wait for nobody */
         if (sbi->catatonic)
@@ -223,21 +239,41 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                 return -EINTR;
         }
 
-        for (wq = sbi->queues ; wq ; wq = wq->next) {
-                if (wq->hash == dentry->d_name.hash &&
-                    wq->len == len &&
-                    wq->name && !memcmp(wq->name, name, len))
-                        break;
-        }
+        wq = autofs4_find_wait(sbi, name, hash, len);
+        ino = autofs4_dentry_ino(dentry);
+        if (!wq && ino && notify == NFY_NONE) {
+                /*
+                 * Either we've betean the pending expire to post it's
+                 * wait or it finished while we waited on the mutex.
+                 * So we need to wait till either, the wait appears
+                 * or the expire finishes.
+                 */
+
+                while (ino->flags & AUTOFS_INF_EXPIRING) {
+                        mutex_unlock(&sbi->wq_mutex);
+                        schedule_timeout_interruptible(HZ/10);
+                        if (mutex_lock_interruptible(&sbi->wq_mutex)) {
+                                kfree(name);
+                                return -EINTR;
+                        }
+                        wq = autofs4_find_wait(sbi, name, hash, len);
+                        if (wq)
+                                break;
+                }
 
-        if (!wq) {
-                /* Can't wait for an expire if there's no mount */
-                if (notify == NFY_NONE && !d_mountpoint(dentry)) {
+                /*
+                 * Not ideal but the status has already gone. Of the two
+                 * cases where we wait on NFY_NONE neither depend on the
+                 * return status of the wait.
+                 */
+                if (!wq) {
                         kfree(name);
                         mutex_unlock(&sbi->wq_mutex);
-                        return -ENOENT;
+                        return 0;
                 }
+        }
 
+        if (!wq) {
                 /* Create a new wait queue */
                 wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
                 if (!wq) {
@@ -263,20 +299,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                 wq->tgid = current->tgid;
                 wq->status = -EINTR; /* Status return if interrupted */
                 atomic_set(&wq->wait_ctr, 2);
-                atomic_set(&wq->notify, 1);
-                mutex_unlock(&sbi->wq_mutex);
-        } else {
-                atomic_inc(&wq->wait_ctr);
                 mutex_unlock(&sbi->wq_mutex);
-                kfree(name);
-                DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
-                        (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
-        }
-
-        if (notify != NFY_NONE && atomic_read(&wq->notify)) {
-                int type;
-
-                atomic_dec(&wq->notify);
 
                 if (sbi->version < 5) {
                         if (notify == NFY_MOUNT)
@@ -299,6 +322,12 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 
                 /* autofs4_notify_daemon() may block */
                 autofs4_notify_daemon(sbi, wq, type);
+        } else {
+                atomic_inc(&wq->wait_ctr);
+                mutex_unlock(&sbi->wq_mutex);
+                kfree(name);
+                DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
+                        (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
         }
 
         /* wq->name is NULL if and only if the lock is already released */